Microcontrollers and IoT

Menu

I have tested several IoT platforms over the last couple of weeks. So I was not too keen to checkout yet another one. However, when I got the annoucement that the Spark Core is shipping I could not resist and ordered one. It arrive in the mail today so I thought I will take it for a spin.
The Spark Core comes in a very stylish little box.
Figure1: Spark Box
To my surprise the box did even includes a breadboard:
Figure 2: Open Spark Core Box
Overall, the box contains the Spark Core board, a breadboard, a micro-USB cable and Spark sticker.
Figure 3: Box Content
It is amazingly simple to get the board up and running. By following these few simple steps:

Download the Spark App for iPhone or Android

Setup an account by register at spark.io

Power up the Spark Core over the USB cable

Start Spark App and log into your wireless network

If everything works well you will get rewarded with the RGB-LED on the Spark board flashing in rainbow colors. Once the Spark Core is connected to you WiFi and paired with the Spark cloud, it took me only a few minutes to get an on-board blue LED blinking.
It very quickly becomes obvious that the Spark team has done a great job setting up an entire end-to-end IoT solution consisting of:

Spark Hardware

Cloud based IDE

Arduino compatible API

Free for life cloud back-end service with a RESTful API

All the Spark Core software is open source. The board uses a CC3000 WiFi Module from TI combined with a 32-bit ARM Cortex-M3 powered STM32F103 from ST Microelectronics. The Spark team has come up with a nice integration of this hardware and the cloud server back end. It is based on the CoAP protocol specification and allows for an easy and energy efficient integrated IoT solution.
The cloud API offers over-the-air (OTA) firmware updating where the input can either be c/c++ source code or binaries. For those that don’t want to use Spark Builder, their cloud based IDE the web site also promises support for desktop IDEs like Eclipse.
So much for today, I will cover more details in future blogs.

There are a lot of WiFi solutions for Makers out there. However many are either expensive, big or outdated. So it is refreshing to look at the technical data of the little known WiFi module available by the name of RTX4100 from RTX Telecom. You may never have heard of RTX Telecom but this Danish design service company specialized in wireless has been around for many years. The module is hardly bigger than a Bluetooth module.
Figure1: on the left a simple Bluetooth HC-5 module and on the right the RTX4100 WiFi Module.
The RTX41xx uses latest WiFi System in a Package (SiP) technology. It features a Nordic Semiconductors 32-bit ARM Cortex-M3 based low power microcontroller. The WiFi is based on a AR41xx SiP from one of the leading WiFi chip manufacturer Qualcomm – Atheros.
The 32-bit application processor is responsible for all the WiFi driver related duties. But an API allows to program custom application into the module. RTX calls the custom programs Co-Located Application or CoLA. Besides the RTX4100 that offers 24 kBytes flash memory and 3 kBytes RAM for custom applications. RTX also offers a pin compatible RTX4140 that provides much more programmable memory for CoLA applications, 512 kBytes flash and 64 kBytes RAM.
The SDK can be downloaded from RTX’s web site together with a comprehensive set of documents and CoLA examples.
On the Hardware side the module offers 30 solder pins that support a variety of I/O functionality:

ADC ports, DAC ports

GPIO ports

UART, SPI, I2C

Timers

RTX has also teamed up with some cloud services. The currently supported cloud partners are: 2lemetry, Exosite, Nabto and Sensinode.
For simple applications like WiFi sensors or actors that require a limited set of IOs and CPU/Memory resources RTX41xx modules can be used stand alone. They are also a great choice for embedded projects based on Arduino that need WiFi. Similar to some of the popular Bluetooth modules you only need a spare UART or SPI interface to talk to the RTX4100.
Unlike Electric Imp that offers you a fully integrated platform form the module all the way up to the cloud, RTX is a much more open and flexible platform where you retain control. However this control also comes at the price that you have to do more software work. The good news is that you don’t have to start from scratch, RTX supports you with quite a bit of Software.

Broadcom is also jumping on the IoT wagon with the WICED platform. The platform is targeting Bluetooth and WiFi applications. The WiFi modules feature the BCM43362 WiFi chip integrated into a System in a Package (SiP) module. The Image below shows a WiFI WICED PCB module with a Murata WiFi SiP Module and a STM32F205 microcontroller. Murata also offers SiP modules that have the ARM microcontroller built in.
On the software side the platform is supported by a feature rich SDK and support for OSs: